FI67464B - ELECTRIC COOK PLATE - Google Patents

Description

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The Federal Republic of Germany-Förbundsrepubliken

Germany (DE) P 2933296.5 (71) Karl Fischer, Am Gänsberg 23, D ~ 7519 Oberderdingen,

Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (72) Karl Fischer, Oberderdingen, Felix Schreder, Oberderdingen,

Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (74) Oy Koister Ab (54) Electric hob - Electric cooktop

The invention relates to an electric hob comprising a hob body with a downwardly directed, annular edge on an outer circumference on which the cover plate rests. Such an electric hob with a central sensing device is known. The cover plate is placed flat on the edge and fastened with two threaded bolts. The cover plate is not very tight and is poorly centered. When, under extreme conditions, such as after shipping, moisture has penetrated the interior of the space shared by the cover plate, it can increase leakage currents.

The object of the invention is to provide an electric hob in which the cover plate is well centered and fitted with an improved seal.

According to the invention, the edge has a notch in which a corresponding projection of the cover plate, directed towards the interior of the hob, engages.

No more open gaps are formed and, above all, it is easily possible to insert a seal in between. Due to the relatively large distance of the support surface 2 674 64 from the heating, the seal is not very exposed to temperature. Preferably, the cover plate is pressed very evenly from the center area.

This shape of the cover plate also makes it possible to fit insulation, which can advantageously consist of an embedded metal foil. In connection with or separately from such a metal foil, a desiccant can be applied which, when the hob is used, regenerates itself due to the high temperature.

In connection with known hobs (DE application publication No. 2,651,848), the electrical connection of the hob takes place via a ceramic connection piece located at one end of a support plate attached to the cover plate. The insulating piece protrudes through the cover plate and the support plate. The connecting wires made of closed rails or wires pass through this and enter the connecting piece parallel to the support plate. Although fixed fitting of the connector has proven to be very suitable, it would be desirable to improve the installation possibilities, especially in connection with the installation of very flat hotplates, and the storage and transport possibilities of such hotplates.

For this purpose, it is proposed to make the heat-insulated connecting wires leading from the electric hob flexible and to lead them to a common, freely movable fitting with its connection pins, the connecting wires being long enough to fit the connection outside the electric hob area.

Although it is known to fit insulated, flexible connecting wires for electric hobs, these were normally very long and provided with free ends. They interfered with handling, had to be shortened during installation, or formed an unnecessarily long wire, which meant losses, made it difficult to get an overall picture during installation, and posed a risk of oi-blockage and otherwise increased the variety of different wire lengths. Although the proposed connector is flexible and suitable for all installation requirements, it is outside the heated area of the hob, but does not interfere with installation. For transport and storage, the connector can be bent so that it does not require a higher height than the electric hob itself. It can be located either turned outwards in the spaces formed between the round hobs or turned inwards in the recess of the hob cover.

In connection with the known electric hobs (DE patent publication No. 2,620,004), a central bolt protruding the lower cover plate and securing the hob to the hob mounting bracket protrudes far over the underside and anti-rotation pins protrude over the underside. The protruding insulation piece also raises the construction height. During storage and transport, the cooking plates had to be stacked by hand using small wooden blocks inserted on the outer edge. The hob can be further improved, in particular for space-saving and safe transport, when the hobs are superimposed on the hobs and the undersides, respectively, with each other turned 180 ° in a circumferentially displaced position, whereby the insulating piece penetrates the recess of the cover plate. In the absence of further advantageously projecting fastening bolts and anti-rotation bolts, the hob can be stacked to a height even lower than its own overall height.

Furthermore, it is possible to stack the hobs in the axial direction precisely in an extension so that the outer edges of the hob pieces rest in line on each other with the centering packaging plate as an intermediate layer. Thus, a massive supporting stack is created, which lowers transportation and storage costs and increases safety.

Thus, it is also possible to support the cover plate on the free bottom edge of the edge of the hob extending around it due to the possibility of stacking, which was previously only possible with disadvantages. The notch on this edge and the corresponding raised protrusion on the cover plate allow for automatic lowering to a 180 ° circumferentially displaced position for packaging.

It is known from DE Patent Publication No. 2,620,004 to screw a threaded bolt into the central pin of a hob body and to fasten the cover plate to it by means of a screw. Therefore, two screwing operations must be performed. In addition, the threaded bolt protrudes far from the hob so that the dimensions of the package are twice as large as the height of the entire hob and, in addition, axial displacement of adjacent hobs must be performed during transport, 4 67464 if it is no longer desired to increase the package dimensions. The purpose of the protruding part of the threaded bolt is to fasten the hob to the handle with another nut screwed on top, so that the hob is tightened downwards.

On the other hand, when the screw is preferably a hollow base screw with external and internal threads, which fastens the cover plate with its base and into which the fixing plate of the electric hob can be screwed in, it is only necessary to screw in the hollow screw to fasten the cover plate. For subsequent installation of the hob, a standard capscrew is then used to secure the hob. The hollow screw is better secured and packing and shipping costs are reduced. In addition, adaptability to different mounting heights is more easily possible while simply using other capscrews.

Other advantages and features of the invention will become apparent from the subclaims and the description in connection with the drawing. Embodiments of the invention are shown in the drawing and will be explained in more detail below.

Fig. 1 shows a cross-section of an electric slurry, a cooking recess or the like built into an electric hob, Fig. 2 is a detailed view taken along line II-II in Fig. 1, Fig. 3 is a sectional view of a variant of Fig. 1, Fig. 4 shows a detail in Fig. 1 5-7 show the detail of Figure 4 of modifications, Fig 8 is a view of the arrow a detail view of Figure 1 VIII in Figure 9 has a central attachment of a detail of one of the hot plate of Fig enlarged representation, Figure 10 shows three stacked one upon the cooking plate, the grounding connection to the equivalent of Figure 1 the cooking plate and the compression means belonging to them, Figure 11 is a top view of a detail of the arrow XI of Figure 10; Figure 12 5 67 464 shows a rotation preventing and optionally working the land doitusliitäntänä a top plate portion, Figure 13 is a fragmentary sectional view of D along the line XIII-XIII in Fig. 12, Fig. 14 shows a partial section of the lower center region of the hob in the installed state, and Fig. 15 shows a rear view of this hob.

Figure 1 shows an electric hob 11 with a cast iron hob body 12 comprising an upper flat and closed hob 13. The unheated central zone 14 is lowered to form an annular hob. The hob piece grips on its outer circumference over an overflow edge 15 of plate material having a substantially U-shaped cross-section, which rests on the pulled-up opening edge 16 of the work plate 17 of the electric hob or cooking recess.

In the heated ring region, the hob is provided with helically running ribs which also form helical grooves 18 between them, in which the heating coils 19 are located in the ceramic immersion mass.

A downwardly directed substantially cylindrical edge 21 protrudes in the circumferential region of the hob body, the lower edge 22 of which is supported by a flanged edge region of a cylindrical, embossed and shaped cover plate. The edge region 23 is joined upwards, i.e. by a shoulder 25 facing the hob, which is located on the inner side of the edge 21 and thus centers the closing lid and the cover plate, respectively.

At one point on the circumference there is a rectangular notch 26 in the edge 21 (Fig. 8) in which the corresponding embossed projection 27 of the cover plate fits and thus ensures a relatively tight closure despite securing the cover plate 24 against rotation by the hob piece. The protrusion 27 of the cover plate, in turn, ensures that the finished hob can be oriented circumferentially during processing during manufacture. Thus, at the edge 21, no inner protrusion is required. Associated with the shoulder 25 is a region 28 of the cover plate projecting back relative to the edge region 23 and a central region 29 projecting somewhat relative to the edge region 23.

67464

In the center of the unheated central zone 14 is a downwardly projecting pin 30 in the hob body into which a closed threaded bore 31 is inserted from below. A hollow cap screw 32, which is shown in detail in Fig. 9, is screwed into this threaded bore.

It consists of a plate-forming or deep-drawing part with a flanged base area 33 having a hexagonal key surface, and an associated sleeve-shaped threaded part 34 in which internal and external threads are printed or extruded. The screw 32 projects through the central tension hole 36 of the cover plate 24 and is screwed into the threads 35 of the bore 31 so that the cover plate 24 is pressed by its edge region 23 for the lower edge 22 of the edge 21 of the hob piece 12. Between the base 32 and the cover plate is placed a plate part 37 (Fig. 2) in the form of a plate strip with a hole 38 on one side through which a screw 32 protrudes, while the other end is somewhat tapered and grips the bent end 38 (Figs. 1 and 2). ) around ground wire 40. The ground wire may be clamped or welded to the plate portion 37. This plate part is thus simply placed like a washer under the screw base 33 and allows a secure earthing. In this case, it is particularly advantageous that the plate part rests flat on the underside of the cover plate 24 during manufacture and transport, and only when necessary is it somewhat bent therefrom. Grounding therefore does not significantly increase the construction height of the hob.

Fig. 9 shows on the left side that the support surface of the base 33 can be provided with a preferably star-shaped groove 41. Correspondingly, the plate part 37 is also provided with a top and bottom side and a cover plate 24 (see Figs. 2 and 15), so that the screw 32 is secured against error. against detachment. However, it is also possible to use other backup methods.

The hob is held in its receiving worktop recess by a handle 42 which rests on the underside of the worktop 17 and has a flat U-shape. Its long back is stiffened by side bends 43. Through the hole 44 in the middle of the bracket, a base screw 45 is inserted, which is screwed into the internal threads in the hollow screw 32. Thus, the hob is tightened with a screw and handle downwards and is securely fastened. Thanks to this type of fastening, it is only possible to work with cap screws, which can be easily fastened with automatic screwdriving equipment. In this case, the screw 32 is a simple sheet metal part and the screw 45 is a simple machine screw. Hitherto, the hobs have been provided with screw bolts screwed into the pins 30 and projecting far beyond the underside of the hob. Two or more nuts screwed to these bolts secured the cover plate and hob to the handle. Thus, space-saving packaging was not possible. Now, instead, the hob only takes up the space it needs in connection with the package, and the additional advantage has been achieved that the length of the screw 45 can always be selected according to the height of the handle. This is especially important when attaching the hob to very shallow mounting recesses. Thus, one type of hob can be used for all bar heights. In the past, hob types had to be equipped with different long screw bolts for this purpose.

The handle 42 is riveted with an upwardly projecting pin 47 which engages a sleeve-like recess 46 formed inwardly in the cover plate and thus secures the hob against rotation against the bracket. In order to allow several installation possibilities of the hob, which is especially important due to the location of the connecting cables, several recesses 46 can be arranged on the circumference, possibly also offset by 90 ° with respect to each other. By fitting the anti-rotation pin 45 to the handle hitherto instead of fitting it to the hob, care is taken to ensure that the overall depth dimensions of the hob remain small. The recess 46 is closed so that the hot interior 48 of the hob formed between the cover plate 24 and the hob body 12 is closed.

Figure 3 shows a variation of the recess 46 which can be selected when the plate from which the cover plate 24 is formed will not be subjected to a very large deformation. The separately made sleeve 46 'is tightly fastened to the opening of the cover plate 24 by means of a double-sided rim 46 ". It is also possible to provide the sleeve, for example, with pressed threads in the area of the rim 46" for later screwing in of the pin.

Fig. 4 shows in detail that a sealing ring 25, which may have a flat or circular cross-sectional shape and is made of a heat-resistant sealing material, is placed between the edge area 23 of the cover plate 24 and the lower edge 22 of the hob edge 21.

8 67464 Silicone rubber, asbestos-containing sealing materials, etc. are suitable for this purpose. Other sealing solutions are shown in Figures 5 and 6, in which Figure 5 the seal 25a consists of a paste placed at an angle between the edge region 23 and the shoulder 25 and distributed on the lower edge 22 and the inner side of the edge when pressed. This embodiment is particularly advantageous for sealing the area of the notch 26.

Fig. 6 shows, at a corresponding point, a prefabricated sealing ring 25b having a Z-shaped cross-section which covers a part of the inner surface of the lower edge 22, the inner side of the edge 21 and the retracted part 28 of the cover plate 24. This sealing ring may be a compression mass made of aluminosilicate fiber and impregnated with a silicone resin-based varnish.

When using a seal on the outer circumference, it is also recommended to fit the seal in the area of the screw 32.

The seal is intended to prevent moisture from penetrating into the interior of the hob 48 and thus e.g. into the immersion mass 20 when the hob is exposed to extreme conditions, e.g. during sea transport. Although the hob itself immediately removes any moisture that has penetrated immediately without generating unauthorized leakage currents before, the sealing still provides additional certainty. Sealing becomes possible in particular by fitting the cover plate to the lower flange, as the seal thus enters a lower temperature range and can be placed better. To date, the cover plates rest on the lower side of the dipping mass 20. Shoulder 25 ensures additional sealing and proper centering.

Fig. 7 shows an embodiment in which the edge 21 'of the hob piece has a stepped groove 49 on its inner underside, so that an outer circumferential edge portion 50 of the edge 21' is formed which extends somewhat further downwards than the support surface for the edge region 23 of the cover plate 24. Here, only in the exceptional case of the risk of water running down the hob can this drip out without being absorbed into the interior by the capillary action 48.

It can be seen in Fig. 1 that, approximately parallel to the piezoelectric plate, there is a metal film 51 in the interior 48, which is in particular a bare aluminum crumb film. It is tensioned between the edge plate 21 and 9 67464 between the cover plate 24 and the seals fitted thereon (see Figures 4-7) and encloses a layer 52 between itself and the cover plate 24, preferably consisting of or containing silica gel or kieselguhr. This material not only provides good insulation, but also that, for example, water which has penetrated with atmospheric moisture is received in a silica gel which acts as a desiccant. As a result of the automatic heating, during the use of the hob, the desiccant always regenerates itself when the water is removed, so that it always remains functional. If a desiccant is used, the metal foil may be provided with holes or the desiccant may be placed in other containers in the interior 48 to ensure its effectiveness.

If extreme conditions for moisture penetration are not to be feared, it is also possible to make the layer 52 from highly heat-resistant insulation materials, e.g. inorganic fibers such as asbestos or other known insulation materials. Together with the metal foil on it, a very effective insulation is formed, which further reduces the already small heat losses due to radiation or conduction downwards in connection with the contact hob. Thus, above all, the temperature of the cover plate 24 is kept low, so that it is also possible to install it in very shallow cooking recesses in the vicinity of the wooden parts of the kitchen furniture.

Fig. 10 shows three stacked hobs which, up to the fact that the hob part 37 '(see also Fig. 11) is provided with a flat plug tongue 53 for connecting the corresponding flat plug of the ground wire 40, are in accordance with the hob of Fig. 1. these same parts. The cutting plane is shifted in Fig. 10 by 45 ° compared to Fig. 1, so that it can be seen that an insulating piece 55 resting on the inside of the cover plate 24 has a temperature limiter in its interior 48 and through openings 57 (Fig. 15) through which heat is well passed. permanently insulated connecting leads 58 from the interior 48 where they are welded to the connecting pins projecting from the immersion mass 20. The basic shape of the insulating body 55 is circumferentially elongate and protrudes through the cover plate in the region of the bulge 60. The connecting wires 58 are connected to a common connecting piece 75 (Figures 10 and 15) of ceramic insulating material, which includes plug or screw connection terminals 76 for connecting the power input wires 78. By fitting the insulator in the radial direction approximately to the center of the annular heated area and dimensioning the connecting wires, the outer edge 77 of the connecting piece 75 is preferably at a distance less than the radius of the hob from its outer edge and can flexibly adapt reversibility and greater vertical movement, but more severely restricts rotation and lateral movement.

Diametrically opposite the insulating piece 55 and at a corresponding radial distance from the center of the hob, there is a recess 61 in the cover plate 24, dimensioned so as to be able to receive the protruding part of the insulating piece in the reciprocating fitting of the hob shown in Fig. The width of the recess is substantially greater than the width of the insulator, so that as can be seen from Figure 10 with both upper Hobs, the connecting wires 58 can be turned inwards and the connecting piece 77 can be located next to the insulating piece in the recess 61. It is also possible to store the connecting piece 77 inverted approximately in the plane of the hob, the connecting wires 58 leading out through the corresponding section of the packing plate 63. Thanks to the recess in the cover plate, it is also possible to pack the hob during storage and transport, especially in a space-saving and safe manner. For this purpose, the hobs are stacked on top of each other with their central axes aligned in each case with their flat hobs 13 and the undersides covered by their cover plates 24 respectively facing each other, with only a sheet or film 62 which may be cross plywood or prespan and has notches selected so that the hob is centered when placed on it. The portions projecting downwardly relative to the outer edge 23 of the cover plate protrude into the notch 64 of the packaging plate 63.

The hobs 11 are in each case displaced 180 ° relative to each other in the circumferential direction, so that the insulating piece 55 with its connecting wires protrudes 11 67464 into the recess 61 and the hob needs a completely smaller packing space than would correspond to its overall height. The edges 21 rest on each other with the packing plate 63 as an intermediate layer, while forming a strong stack which does not tend to tilt. The overlapping of the hobs also contributes to this in particular. The packaging plates 63 have a plurality of notches 64 side by side and in succession, corresponding to the desired size of the packaging or peeling pallet, so that a large number of hotplates can be stored and transported in a massive array, thus saving not only storage and transportation costs but also increasing safety. Packing can also be done completely automatically by means of grippers.

The hotplates of Figure 10 lack a silica gel filler. For insulating purposes, only the aluminum crimp film 51 is placed parallel to the cover plate 24.

Figures 12-15 show another device for preventing the hob from rotating with respect to the fastening parts, e.g. the handle 42. For this purpose, a plate part 65 is provided which has the shape of a flat rectangular strip extending through the fold area 66. The side sections 67 separate at the ends of the parts 68 the edge areas which are bent together or rolled from the ends (see in particular Fig. 13) so that the ends are rod-shaped. The portions 68 have U-shaped cuts 70 so as to form plate strips 71 bent outwardly from the plane of the portions 68. Fig. 14 shows this plate part 37 in Fig. 1 fastened to the hob with a screw 32 and secured to it against rotation by a strip 71 projecting through an opening 72 in the hob. Instead of the opening 72, a corresponding embossed projection could also be arranged without piercing the cover plate. The ends 69 are preferably bent only about 90 ° during the installation of the hob in a slurry or the like, which is easily possible due to the cuts 67. In this case, it is only necessary to bend this end 69, which must be inserted into the hole 73 of the fastening strap 42 '. Also in this case, the prevention of rotation is achieved without increasing the transport space.

Fig. 12 shows in broken lines that the anti-rotation plate part 65 could be provided with a third part 37 ", at the end of which a flat plug tongue 53 is fitted to connect the earth conductor. Thus, a single part can perform a dual function of anti-rotation and earth connection. it is also possible, as shown in Fig. 15, that the plate part 37 'is additionally screwed to the anti-rotation plate part 65 by a screw 32. Since the part 65 is otherwise secured against rotation, a groove 41 is sufficient without it being necessary with the cover plate.

Since the hobs are preferably packed in a 180 ° displaced position, the recess 61 is diametrically opposite the insulating part 55. Of course, it would also be possible to carry out the transfer at another angle. Accordingly, the recess 61 should likewise be displaced at a different angle to the insulating body 55. In any case, the barrier plate has the advantage that, despite its sufficient rigidity, it is easy to manufacture due to its relatively low design and provides a well-insulating closed interior. In the case of an embodiment with a central opening for a central sensor box, the support of the cover could take place both on the outer edge 21 and also on the inner edge surrounding the notch of the sensor via the shoulder of the cover plate. It could also be fastened with hollow screws. In this case, the pin with internal threads would thus not be located centrally, but e.g. in the area of the outer edge.

Claims (10)

674 64 An electric hob comprising a hob body having a downwardly directed annular edge on the outer periphery and a cover plate resting on the edge and a portion (25) facing the interior (48) of the hob associated with a free lower edge (22) of the edge (21). to the edge region (23) and together with the inner circumference of the edge (21) to center the cover plate (24), characterized in that the edge (21) has a notch (26) into which a corresponding projection (27) of the cover plate (24) faces the interior of the hob. sticks. Electric hob according to Claim 1, characterized in that a seal (25, 25a, 25b) is preferably folded at an angle between the cover plate (4) and the edge (21), which is particularly preferably a paste-shaped silicone rubber or aluminosilicate fiber material, impregnated with a hard heat-resistant varnish. Electric hob according to one of the preceding claims, characterized in that the lower edge of the edge (21 ') has an outer circumferential edge part (50) projecting downwards over the support edge (49) of the cover plate (24). Electric hob according to one of the preceding claims, characterized in that the side of the interior (28) closed by the cover plate (24) of the electric hob (11) preferably has an insulation (51) containing a metal film, e.g. an aluminum wrinkle film tightened between the cover plate and the edge. , 52). Electric hob according to one of the preceding claims, characterized in that the cover plate is fastened to the pin of the hob body with a screw (32) and the screw also acts to fasten the electric hob to a slurry, recess or the like, the screw (32) being hollow outer and inner. a threaded head screw which secures the cover plate (24) with its base (33) and into which the fastening screw (45) of the electric hob (11) can be screwed in and that the screw (32) is preferably in a flanged edge base (33) and a plate sleeve with compressed threads . Electric hob according to Claim 5, characterized in that the side of the screw base area (33) facing the cover plate (24) has a groove (41) which is optionally cooperating with the part on or between the cover plate (24). (37, 65) preferably with a star-shaped groove (41) to secure the screw (32). Electric hob according to one of the preceding claims, characterized in that at least one plate part (37, 37 ', 65) is tightened between the screw (32) holding the cover plate (24) and screwed into the pin (30) of the electric hob (11) and the cover plate (24). ) having at least one portion (68) projecting outwardly from the central region, preferably made to accommodate the ground wire (40) by fitting, enclosing or squeezing. Electric hob according to Claim 7, characterized in that at least one of the parts (68) has bendable ends (69) of the cover plate (24) which, in order to secure the electric hob (11) against rotation, co-operate with fastening parts in the hob, recess or the like. (42 ') and in particular that the plate part (65) is torsionally fixed to the electric hob (11) by means of bent strips (71) of plate material which penetrate the notches (72) in the cover plate. Electric hob according to one of the preceding claims, characterized in that its lower cover plate (24) has at least one recess (46, 46 ') formed on the inside of the hob, shaped from the cover plate or fitted into the opening of the cover plate. to receive a screwable anti-rotation pin (47). Electric hob according to one of the preceding claims, characterized in that the cover plate (24) is pressed on the edge (21) by means of a fastening element (32) acting in the central region. 67464 15